In the scene when Annabelle leaves the end-of-year ball with St. Peters to retrieve her guitar and the music for a song she wrote earlier, a poster is plainly visible on the wall above her bedside table, featuring the band that originally wrote and performed the song she is about to sing.
Actress Erin Kelly was approached by director Katherine Brooks randomly in a theatre audience and began working on the script/movie with her for three years before the movie began production. Actress Diane Gaidry was hired three days before the movie began production.
During Annabelle's first English class with Ms. Bradley, random quotes and poems are written on the chalk board, which becomes visible while Ms. Bradley quotes a poem by Walt Whitman. During this time, the lyrics "open your heart, catch my disease" followed by "B. Lee" from Ben Lee's 2005 single "Catch My Disease" can be seen in the lower left corner of the board, written in yellow chalk. This is presumably a joke quote, that has no relevance to the scene.